Vapor phase production of halonitroethanes



j VAPOR PHASE PRonUcrro 'oF HALONITROETTIANES "No Drawing. ApplicationJune 20, 1953 V I .Serial No.743,5 05 r 8 Claims. c1. 260-644)"" 4 Ourinvention pertains to the production of halonitroethanes having at leastone halogen beta to the carbon carrying the nitro radical by thehalonitration of haloethylenes and more particularly to the productionof halonitroethanes by the vapor phase halonitration of haloethylenes bydinitrogen tetroxide and halogens.

Unsubstituted olefins have previously been shown to react withmixturesof halogen and dinitrogen tetroxide to form the correspondingbeta-haloalkyl nitrates (G. B. Bachman and T. J..Logan, 'I. -0rg.'fchem, 21, 1467 (1956). in co-pending application, Serial No. 743,494,filed June 20, 1958,..we have disclosed the production ofhalonitroethanes having at least one halogen beta to the carbcnca'rryingthe nitro radical by'v the liquid phase halonitration of haloethyleneswith dinitrogen tetroxide and halogens. We have now discovered that bycarrying outthehalouitration of haloethylenes in the vapor'phase,

the halonitration takes place in adifierent manner so as 'to produce.compounds differing in structure from those produced by the liquid phasehalonitration of the halo- The halo-Z-nitroethanes of our invention areuseful as solvents for various purposes and particularly as soilfumigant, being readily sprayed onto or introduced into the soil in themanner and in the amounts customarily employed in soil fumigation. I

the scope of this specification and attached claims:

EXAMPLE I actor maintained at a temperature of 325 C. Vinyl chloridepreheated to a temperature of 250 C. was then passed at a rate of 9.75g./minute into the mixture of dinitrogen 'tetroxide and bromine in thereactor. The

ethylenes. Our process, therefore, permits the production of any-desiredisomer of the halonitroethanes merely by regulating the reactionconditions under which the halonitration of the haloethylenes takesplace.

Our process for the production of halonitroethanes having at least onehalogen beta to the carbon carrying the nitro radical consistsessentially of contacting in the vapor phase a mixture of dinitrogentetroxide, halogen, and haloethylene, the nitrating and the halogenatingagents being preferably first mixed and the resulting mixture thencontacted with the haloethylene, the latter preferably being preheatedbefore being contacted with the other reactants in the reactor. a

In carrying out our process we can use the haloethylenes vinyl chlorideand vinyl bromide. As a nitrating agent We use dinitrogen tetroxide andfor the chlo- I rinating agent the halogens chlorine and bromine.

The reaction is carried out in the vapor phase, at temperatures rangingfrom 225 C. ;to 350 0., depending primarily upon the haloethylene beingtreated, the reaction with vinyl bromide taking place at a substantiallylower temperature than that required for vinyl chloride. The ratios ofthe reactants can be varied somewhat without materially reducing theeffectiveness of the re. action. We have found, however, that usingvinyl chloride, chlorine and nitrogen dioxide, as the reactants, the

l preferred mole ratio is of theorder of 7.79/0.541/1.0

respectively. We have, however, obtained almost equally chlorine to0.3..

satisfactory results when reducing the moleratio of the contact time forthe reactants was 4.0 seconds. During a period-of 150 minutes, 105 gramsof bromine (0.937 mole), 97.5 (2.12 moles) of dinitrogen tetroxide and-14625 g. (23.4 moles) of vinyl chloride were passed through the reactor.This amounted to a mole ratio'of 11.1 vinyl chloride/0.31 bromine/ 1.0dinitrogen 'tetroxide. A yield of 23.8 grams of2-bromo-1-chloro-nitroethane was obtained based ou-the vinyl chloridecon} s'umed. v

' EXAMPLE II This run was made exactly as described in Example I withthe exception that the reactants were used in the mole ratio of2.93'vinyl chloride/0.34 bromine/ 1.0 dinitrogen tetroxide but thereaction was continued for only 90 minutes.

The reaction product consisted of two layers, the upper aqueous layerWeighing 8.2 g. and the lower organic layer weighing 79.3 g.Distillation oi the organic layer gave 16 g. of2-bromo-l-chloro-l-nitroethane, B.P. 68

C. (6.7 mm.), 12 1.4970; 1.9 g. of high boiling residue believed to be4-bromo-1,3-dichloro-l-nitrobutane; 27.4 g. ofaliquid believed to be1,2-dibromo-1-chloroethane; and 27L0 g. of a low boiling unidentifiedliquid.

EXAMPLE III The chloronitration of vinyl bromide was carried out asdescribed in Example I above. The mole ratio of the reactants was 9.78vinyl bromide/2.27 chlorine/ 1.0 diuitrogen tetroxide. In this case,however, the vinyl bro mide was preheated to a temperature of 220 C. andthe temperature of the reactor was maintained at 250 C. and the reactionwas conducted for a period of 50 minutes. Vacuum distillation of thereaction products gave 18.4 g. of l-bromo-l-chloro-2-nitroethane,- Bl.54.5 C.

(2.0 mm.) from 738.5 g. (6.90 moles) of vinyl bromide,

113.73 g. (1.60 moles) of chlorine and 32.5 g. (0.706

mole) of dinitrogen tetroxide.

EXAMPLE IV The table which follows shows thefresults of a series ofexperiments carried out at different reaction temperatures and usingdifierent mole ratios ofxvinyl chloride, chlorine and dinitrogenvteti'oxide.

pat nted Apr. 19, 1960 3 Table RIOLE RATIO AND TEMPERATURE DEPENDENCE OFCONVERSION TO 1,2-DICHLORO-l-NITROETHANE Temper- Mole Ratio, Conv. onPer- Per- Run nture CH2= CHCI/ percent cent cent Ola/N03 OH=CHO1 On 012On NO:

290 7. 79/. 541/1. 2. 43 34. 80 18. 92 300 7. 79/. 541/1. 0 3. 79 40. 2421. 77 310 7. 79/. 541/1. 0 3. 47. 52 25. 71 320 7. 79/. 541/1. 0 3. 7353. 76 29. 09 330 7. 79/. 541/1. 0 4. 26 61. 36 33. 20 340 7. 79/.541/1. 0 3. 14 4.5. 20 24. 416 350 7. 79/. 541/1. 0 2. 35. 36 19.35 3307. 79/. 541/1. 0 3. 76 54. 16 29. 31 335 7. 79/. 541/1. 0 3. 71 63. 4428. 92 840 7. 79/. 541/11] 3. 49. 50. 32, 27. 23 345 7. 79/. 541/1. 0 3.32 47. 76 e 25. 85 355 7. 79/. 541/1. 0 1. 74 25. 04 1-3. 56 525 7. 79/.541/1. 0 4. 03 58. 00v 3.1. 38 330' 7. 79/. 541/1. 0 3; 96 57. 04 30. 87300 7. 79/. 303/1. 0' 3. 02 77. 71 23. 310 7. 79/. 303/1. 0 3. 27 84.00v25. 45 320 '7. 79/. 303/1. 0' 3: 38' 87. 00 26. 36 340 7. 79/. 303/1. 03.40 80.86 27. 23 300 -7. 79/. 6/1. 0 4. 25 47. 28 15 310 7. 79/. 6/1. 04. 54. 32 3E. 09 320 7. 79/. 6/1. 0 4. 72, 52. 47 36. 80 330 7. 79/.6/1. 0 3. 73 41. 48 29. 09 340 7. 79/. 6/1'. 0' 2. 48 27. 59 19. 35 3107. 79/. 303/1. 0 3.07 78. 75 23. 320 7. 79/. 303/1. 0 3. 55 02. 55 28.05330 7. 79/. 303/1. 0 3. 48 89. 43 27. 10 330 7. 79/. 303/1. 0 4. 14 106.57 32. 29 335 7. 79/. 303/1. 0 3. 101.71 30. 82

7 ethylenes, the step which comprises reacting in the vapor phase amaterial selectedfrom the group consisting of chlorinated ethylenes andbrominated ethylenes with dinitrogen tetroxide and a halogen selectedfrom the group consisting of bromine and chlorine, the reactiontemperature. with the chlorinated ethylenes being within the range of300-350 C. and with the brominated ethylenes between 225 and 275 C.

2. The process of claim 1 wherein said halonitration is effected usingfor each mole of dinitrogen tetroxide from 1 to 20 moles of'halogenatedethylenes and from 1.0 to 5.0 moles of halogen.

3. The process of claim 1 wherein said halogenated ethylenes are passedinto a mixture of dinitrogen tetroxide with the desired halogen.

4. The process of claim 3 wherein the halogenated ethylenes arepreheated prior to introduction into the mixture of dinitrogen tetroxideand halogen.

5. In a process for the production of Z-bromo-l-chloronitroeteane by thehalonitration of vinyl chloride, the step which comprises passingpreheated vinyl chloride into a mixture of dinitrogen tetroxide andbromine, said mixing being effected in the vapor phase at a temperatureof approximately 325 C. i

6. Ina process for the production of 2-bromo-1-chloronitroethane. by,the. halonitration of vinyl chloride, the

step. which comprises. passing preheated vinyl chloride into a mixtureof dinitrogen tetroxide and bromine. while maintaining the reactionmixture, in. the vapor phase at a temperature of approximately 250 C.

7. In a process for the production of l-bromo-l-chloro- 2-nitroethane,the step which comprises passing preheated vinyl bromide intoa mixtureof dinitrogen tetroxide and chlorine while maintaining the reactionmixture in the vapor phase at a temperature of approximately 250 C.

8. In a process for the production of 1,2-dichloro-1- nitroethane, thestep which comprises passing preheated vinyl chloride into a mixture ofdinitrogen tetroxide and chlorine while maintaining the reaction mixturein the vapor phase at a temperature ranging from 300 to 350 C.

References Cited in the file of this patent UNITED STATES PATENTSpounds," vol. I, page 688 (1950), Oxford.

Stevens et al.: J.A.C.S., 80, 338-39, January 20, 1958.

1. IN A PROCESS FOR THE HALONITRATION OF HALOGENATED ETHYLENES, THE STEPWHICH COMPRISES REACTING IN THE VAPOR PHASE A MATERIAL SELECTED FROM THEGROUP CONSISTING OF CHLORINATED ETHYLENES AND BROMINATED ETHYLENES WITHDINIROGEN TETROXIDE AND A HALOGEN SELECTED FROM THE GROUP CONSISTING OFBROMINE AND CHLORINE, THE REACTION TEMPERATURE WITH THE CHLORINATEDETHYLENES BEING WITHIN THE RANGE OF 300-350* C. AND WILTH THE BROMINATEDETHYLENES BETWEEN 225* AND 275* C.